Shirt collar



FIG. 1 is a front view of a shirt collar showing my new design, portions thereof being show in broken lines for illustrative and environmental purposes only and the broken lines forming no part of the claimed design;

FIG. 2 is a enlarged front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a front view thereof showing the collar in an unbuttoned state, portions thereof being show in broken lines for illustrative and environmental purposes only and the broken lines forming no part of the claimed design. 

I claim the ornamental design for a shirt collar, as shown and described. 